My shallow sandbed turns black!

scarab65 · 04/10/2008, 05:09 AM

I have a 100 gal tank for 4.5 years. Tank consist of mainly SPS and some LPS. Running a remote DSB coupled with a refugium of chaeto in the sump. My sand bed is around half inch to an inch Grade 0 sand.

Recently I've been getting brown film algae growth on the sand even when I'm getting almost negligible PO4 and NO3. When I dig into the sand it is all black. I stir it and leave it for a few days and the same thing returns, brown film algae on top and black on the inside as well. It seems that the sand has an anaerobic region and caused H2S to build up. But my sand is only half an inch. Is that possible?

Corals and fish are doing fine. In fact I'm experiencing good growth for my SPS but the brown film algae and the black sand thing is frustrating and the makes the tank very unsightly.

Any remedy or suggestion is greatly appreciated. Thanks in advance.

Electrobes · 04/10/2008, 05:31 AM

I had the same issues with my shallow sand bed about 2 years ago, right before I left the hobby for a year. As much as it sucked the only remedy I could think of to wipe it out in one shot before it got worse (And it will) was to replace the sand bed.

I do have a question though.. in the 4.5 years you've had your tank how long has that sand bed been there, and what equipment did you have.. and how long did you have them for each??

scarab65 · 04/10/2008, 06:41 AM

The sand bed has been there since Day 1. It used to be thicker about 3 to 4 in but I've reduced it to this thickness about 3 years ago.

Equipment as in tank equipment, skimmer, CR and stuff?? If so, the list is in my signature at the bottom and I've had those at least 2 years. Haven't change any equipment lately.

Oh no replacing the sand bed will be quite a massive job......!

04/10/2008, 05:09 AM	#1
scarab65 Registered Member Join Date: Jul 2004 Location: Singapore Posts: 427	My shallow sandbed turns black! I have a 100 gal tank for 4.5 years. Tank consist of mainly SPS and some LPS. Running a remote DSB coupled with a refugium of chaeto in the sump. My sand bed is around half inch to an inch Grade 0 sand. Recently I've been getting brown film algae growth on the sand even when I'm getting almost negligible PO4 and NO3. When I dig into the sand it is all black. I stir it and leave it for a few days and the same thing returns, brown film algae on top and black on the inside as well. It seems that the sand has an anaerobic region and caused H2S to build up. But my sand is only half an inch. Is that possible? Corals and fish are doing fine. In fact I'm experiencing good growth for my SPS but the brown film algae and the black sand thing is frustrating and the makes the tank very unsightly. Any remedy or suggestion is greatly appreciated. Thanks in advance. __________________ Francis Current Tank Info: 100 gal with 90% SPS / 2x250W Hamilton 14K MH / 4x54W blue & actinics ATI T5 / 30 in ht by 8 in dia Reef Maniacs Beckett recirculation skimmer run by Iwaki MD55 and MD40 / 0.5hp Daeil chiller / 4- chamber Reef Maniacs CR / 2xTunze 6100

04/10/2008, 05:31 AM	#2
Electrobes Montipora type guy Join Date: Dec 2003 Location: Fort Myers, FL Posts: 2,945	I had the same issues with my shallow sand bed about 2 years ago, right before I left the hobby for a year. As much as it sucked the only remedy I could think of to wipe it out in one shot before it got worse (And it will) was to replace the sand bed. I do have a question though.. in the 4.5 years you've had your tank how long has that sand bed been there, and what equipment did you have.. and how long did you have them for each?? __________________ Christian Current Tank Info: 100G Half Cylinder

04/10/2008, 06:41 AM	#3
scarab65 Registered Member Join Date: Jul 2004 Location: Singapore Posts: 427	The sand bed has been there since Day 1. It used to be thicker about 3 to 4 in but I've reduced it to this thickness about 3 years ago. Equipment as in tank equipment, skimmer, CR and stuff?? If so, the list is in my signature at the bottom and I've had those at least 2 years. Haven't change any equipment lately. Oh no replacing the sand bed will be quite a massive job......! __________________ Francis Current Tank Info: 100 gal with 90% SPS / 2x250W Hamilton 14K MH / 4x54W blue & actinics ATI T5 / 30 in ht by 8 in dia Reef Maniacs Beckett recirculation skimmer run by Iwaki MD55 and MD40 / 0.5hp Daeil chiller / 4- chamber Reef Maniacs CR / 2xTunze 6100